1. Technical Field
This invention relates to medical devices for animals, and more particularly to an anchor implanted behind the animal's ear, and a medicant-dispensing or diagnostic insert with analog display for use therewith.
2. Description of the Prior Art
The care and raising of animals has always required devices for communicating an animal's condition to a human person, because of the vast communications gap between man and other species. Such devices can be separted into active devices such as conventional thermometers and sphygmomanometers which are applied only when the human is in immediate need of the information provided thereby, and passive devices which continuously provide information on the animal's condition in a form which is readily understood by a human. An example of one such passive temperature sensing device is found in Kelly et al. U.S. Pat. No. 4,083,364.
Kelly discloses a head-mounted retaining device and an associated binary state temperature indicating insert for detecting fever conditions in animals. The Kelly retainer is inserted through the animal's skin into the subcutaneous fascia behind the ear. The retainer has a flange underlying a flange of the insert, and a sleeve capable of radial expansion to cooperate with the flange of the retainer to hold the retainer in place.
Once the retainer has been implanted, the Kelly temperature sensing insert is inserted into the animal through the hollow sleeve of the retainer. The insert remains in its initial, unactivated state until it is activated by the presence of a fever condition in the animal. A fever condition, in which the temperature of the subcutaneous fascia surrounding the tube is elevated, melts a meltable element in the insert which allows a spring-powered piston to descend, uncovering a brightly covered surface portion of the insert and thereby signalling that the animal's temperature has crossed the threshold identified by the melting temperature of the selected meltable element. The binary-state Kelly insert operates in only two states: the initial unactivated state and the final, completely expanded state. The extent of the fever, i.e. the degree to which the animal's body temperature has risen, is not communicated by the device, and must subsequently be determined by other means such as a conventional thermometer.